When did the magi (wise men) who visited Jesus start to be called kings instead?
It seems somewhere in history someone got mixed up and changed the magi (wise men) in the Christmas story into kings. This is evident in modern tradition, where the magi are depicted as three men with kingly garments and crowns, or songs such as "We Three Kings". But the Bible makes no mention of that they were kings, it calls them magi (that is, wise men, astrologers, the first century Mesopotamian version of scientists and scholars). When and how did this error come into being?
Note: Yes, I am well aware that the number of magi that visited Jesus may have been something other than three. There may have been two, three, four, ten, or fourty-two for all we know. There were three gifts, but the Bible never mentions the number of magi. So please don't lecture me about it, thanks!